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Cyclopentasiloxane vs Sodium Sulfite: which is worse?

Quick answer: Sodium Sulfite carries the heavier risk profile. Cyclopentasiloxane is restricted in the EU and allowed in the US; Sodium Sulfite is in the EU and in the US.

PropertyCyclopentasiloxaneSodium Sulfite
EU statusRestricted
US statusAllowed
Risk levelmedium
Banned in
Restricted inEuropean UnionUnited States (banned from fresh produce and salad bars per FDA 1986 action), European Union (ADI 0.7 mg/kg body weight as sulfur dioxide equivalent), Australia (mandatory labeling if above 10 ppm)
Categoryendocrine disruptoradditive
Where it hideshair serum, primer, deodorant

What is Cyclopentasiloxane?

Cyclopentasiloxane is a volatile silicone (D5) used for smooth, silky texture.

What is Sodium Sulfite?

Sodium sulfite is an inorganic sulfite salt used as a food preservative and antioxidant. It releases sulfur dioxide when it contacts water or acid, which acts as the active antimicrobial and antioxidant agent. Part of the broader sulfite family of food additives (including sulfur dioxide E220, sodium bisulfite E222, and others).

Documented risks

Cyclopentasiloxane: Persistent and bioaccumulative; the EU restricts D5 in wash-off products over environmental and endocrine concerns. The US has no restriction.

Sodium Sulfite: Sulfites are among the more significant food allergy/intolerance triggers. An estimated 1 in 100 people, and up to 5% of asthmatics, are sulfite-sensitive. Reactions can include urticaria, angioedema, bronchospasm, and in severe cases anaphylaxis. Sulfite-induced asthma can be severe; several deaths attributable to sulfite-triggered anaphylaxis have been documented. The FDA banned sulfites from fresh produce and restaurant salad bars in 1986 after several deaths and severe reactions were linked to sulfite-treated salads. FDA mandates that sulfite content above 10 ppm be declared on US food labels. All forms of sulfites (E220-E228) share these sensitization concerns.

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